Semiautomatic pistol with blowback breechblock



SEMIAUTOMATIC PISTOL WITH BLOWBACK BREECHBLOCK' Filed June 4, 1948 E. J.slMoNsoN ETAL Jan. 24, 195o 2 Sheets-Sheet'l 1 Jan. 24, 1950 E. J.slMoNsoN ETAL SEMIAUTOMATIC PISTOL WITH BLowBAcx BREEcHBLocxZ'Sheets-Sheet 2 Filed June 4, 1948 N QL Patented Jan. 24, 1950SEMIAUTOMATIC PISTOL WITH BLOWBACK BREECHBLOCK Ernest J. Simonson andJoan Carter Simonson, Muskegon, Mich.

Application June 4, 1948, Serial No. 31,177

3 Claims. 1

This invention relates to ilrearms and more particularly to asemi-automatic pistol with a blow-back breech block.

A main object of the invention is to provide a novel and improvedsemi-automatic pistol which is simple in construction, inexpensive tomanufacture and which is reliable in performance, said not require anymilling operations, the barrel and rlng mechanism being secured in saidmain body in a simple manner and wherein wearable parts are very easy toreplace whenever required.

f Further objects and advantages of the invention will become apparentfrom the following description and claims, and from the accompanyingdrawings, wherein:

Figure 1 is a vertical longitudinal cross-sectional view taken through asemi-automatic pistol constructed in accordance with the presentinvention.

Figure 2 is a horizontal cross-sectional view taken on line 2-2 ofFigure 1.

Figure 3 is a cross-sectional view taken on line 3-3 of Figure 1.

Figure 4 is a cross-sectional View taken on line 4-4 of Figure 1.

Figure 5 is a side elevational view of the semiautomatic pistol ofFigure 1.

Figure 6 is a fragmentary longitudinal vertical cross-sectional detailview taken through the upper rear portion of the pistol of Figure 1,showing a cartridge being loaded from the magazine into the ring chamberof the pistol responsive to the rearward movement of the breech block.

Figure 7 is an enlarged cross-sectional detail view taken on line 'I-'Iof Figure 5.

Figure 8 is an enlarged cross-sectional detail viewA taken on line 8-8of Figure 1.

Referring to the drawings, II designates the main body of the pistol,said main body being made, for example, as a die casting and beingformed with a top frame portion I2 and with a grip portion I3. The bodyis further formed with the nger guard portion I4. The trigger of thepistol is designated at I5 and is pivoted within the top frame portionI2 at I6.

Top frame portion I2 is formed with a longitudinal bore which contains aWear sleeve IT,- said sleeve being split longitudinally and engagingwith a longitudinal internal rib I8 formed in said bore, wherebyrotation of sleeve I1 in the bore is prevented. Slidably positioned inthe sleeve I'I is a breech block I9, said block having a forwardlyextending tubular portion 20. Secured within the forward end of tubularportion 20: as by welding or brazing, is a stop ring 2|. Secured tobreech block I9 is a finger-engaging projection 22 extending laterallythrough a longitudinal slot 23 formed through the rear portions ofsleeve I1 and top frame portion I2.

Threaded into the forward end portion of top frame portion I2 of thepistol body is a plug member 24 formed with an elongated rearwardlyextendingbarrel 25 terminating in a ring chamber member 26. The memberdefined by elements 24, 25 and 26 is axially 'formed with-a rifled bore21. .As shown in Figures 1, 2 and 6, the rear end of member 26,converges inwardly to- Ward the end of bore 21 and defines a conicalrecess 28 adapted to receive the rim of a cartridge 29, when saidcartridge is in firing position in member 25, as illustrated in Figures1 and 2. Encircling barrel 25 is a coiled spring 30 which bears betweenring 2I and member 26 and biases the breech block I9 forwardly towardthe position shown in Figures 1 and 2.

Slidably mounted in breech block I9 is the firing pin 3I, said pin beingprovided with a rear head portion 32. Head portion 32 is located in abore containing a spring 33 encircling pin 3l and biasing head portion32 rearwardly toward a position wherein it projects slightly from therear end of block I9. In this position the pin 3I engages the rim of thecartridge 29 in chamber 26 and when the head portion 32 is struck, aswill be subsequently described, the pin 3l iires the cartridge.

The grip portion I3 is formed with a cavity 34 in the upper portion ofwhich is pivotally mounted, by a transverse pin 35, the hammer 36, saidhammer being shaped generally as the sector of a circular disc. SleeveI1 is longitudinally slotted at 37 to allow hammer 36 to rotate upwardlyinto striking contact with the end of head portion 32, as shown indotted view in Figure 1. Pivotally engaging the hammer 36 rearwardlyadjacent pin 35 is the top loop 38 of a twisted wire rod member 39 whosebottom end is received in a recess 40 formed in the bottom of cavity 34.Designated at 4I is a Sear bar formed with a sharp bottom bend 42pivotally engaging in a V- shaped recess 43 formed forwardly adjacentrecess 46 in the bottom of cavity 34. Bend 42 terminates in an aperturedarm 44 through which the twisted wire rod 39 slidably passes. Encir- 34with another cavity 46 which receives the i cartridge magazine 41.Magazine 41 is conventional in structure and is releasably held incavity 46 by a spring-biased detent lever .48 pivotally carried by gripportion I3 at its bottom end fand engaging a notch in the rear wall A ofthe .magazine to lock the magazine in place. The detent lever 48 may bemanually rotated counterclockwise from the position shownin Figure 1^to`release the magazine. The magazine contains a follower spring 49 actingupwardly on a follower .block 5I).

The cartridges are stacked above the `block 55 and are lurged upwardly.by the .action of spring 43. The top end .of .magazine 41 is open andis formed with upwardly-.inclined .inwardly-convergent anges 5I,.5|which-guide .the cartridges toward the firing chamber as -Saidcartridges 4are moved upwardly. The 4.tubular breech block extension 20is suitably apertured at -52 forwardlyof the block I9 toprovide-apassage for the upward movement vof Athe cartridges f into thefiring chamber when the .breech .block is in a rearwardly movedposition, as shown in .'Figure 6.

Hammer 36 is formed with anarcuatepassage A53, eccentric withrespectto-,pin 35, which1extends from its bottom edge to its top edge,land'extending through said passage and longitudinally movable-thereinis a .curved vertical depending hook element 54 formed at the rear endof :a -sear rod 55. Sear rod 55 is-formed of stii wire aand extendshorizontally aroundzthe top.end 1of=maga zine 41, passes transverselythrough the .upper forward portion of trigger I 5, .as shown at .56,`and is secured at -its forward end :to the .upper y portion of a coiledspring 51 seated Ain a recess 58 formed in body H, at .the trigger guardfporvtion I4. The transverse searrod'portion'561makes a vpivotalconnection with the'upper forward por tion of trigger I5, and when the`ltrigger -I 5 fis pulled rearwardly, the Sear rod 55 is moved`=longitudinally forwardly, compressing spring 51, the end of hook element 54moving the sear bar 41'I :forwardly out of engagement with the notch inhammer 35. This releases the hammer, whereby the spring `is allowed toexpand and rotate the centric passage 53 and the end of the hook ele-rment v54 slips into the opening 54', releasing the vpressure of saidhook element on the sear'bar 4I..

The sear bar 4| is then returned by spring 45 :into contact with thesmaller end of hammer '36.

' Rearwardly of the ring chamber portion '26, s'leeve I1 is vformedopposite slot 23 with an fin- -wardly struck lug 59, breech block I9being formed with a'longitudinal groove 6I] slidably Areceiving said lug59, whereby the breech block' is longitudinally slidable inthe sleeve I1 and vis held against axial Arotation therein. Lug 591s iorme with aninclined inner edge 6I which is engaged by a rearwardly moving cartridgeshell after explosion thereof and causes said shell to be ejectedlaterally through the slot 23, as will be presently explained.

Secured to the rear end wall of the bore cavity dened by sleeve I1 is acushion member G2 of `suitable resilient material, such as rubber or the'.like, which cushions the rearward impact of the breech block I9 onrecoil.

To cock the pistol, breech block I9 is manually retracted by means ofprojection 22. As said lbreech block uncovers the opening 52 communi--cating with magazine 41, the uppermost car- `tridge 29 :therein ismoved upwardly into the inclined position shown in Figure 6, the nose ofthe cartridge entering the conical recess 28 and being moved into theend of bore 21. When the breech block is released, it pushes thecartridge into the ring chamber portion 2'6 and the parts .assume.thepositions .shown inligure l. -It will benoted .that rearwardmovement of .the breech -block rotates lthe 'hammer .36 .downwardly .and.allows .the .top end .of .sear .har 4I to interlock withthemotchintheforwardend of the hammer,

so that 4when the vbreech block is released, the -hammer is held bythesear bar inthe cockedpo- .sition .of Eigure .1.

lWhen the trigger 'is pulled, the .end of hook .portion .54 moves .thesearlbar 4I forwardly out .of engagement with=the Vhammer notch,.asabove explained, .and .said .end .enters opening 5I' .as the .hammer .isrotated .upwardly by spring 45 to .strike :the lring .pin head .32 .andre the car r tridge. `'.'llhe lead .pellet .is .blown -forwardly through`the .bore -21. The recoil of the .exploding gases moves the cartridgeshell and breech block I9 rearwardly. The `shell engages `the inclined.lug zedge Il and is ejected .laterally through the slot 23.

The rearward movementof breech block 19 o nrecoilrotates-hammerrdownwardly and the top .end Kof .sear -barv 4Ilagain interlocks with 4the notch .in :the 'forward `end `of saidhammer. At the same time a new cartridge is moved upwardly by the actionof the spring-biased follower block 50, and enters the space betweenbreech -block I9 .and .firing chamber l2E in the position of Figure 6.Spring 30 is compressed vby the rear- 'ward recoil -movement of thebreech block, and after the recoil force is spent said spring returnsthe .breech block to the position shownin Figure l. Upon release oftrigger ;I5.spring 51 moves 'element-54 'rearwardly out of opening 54',whereupon the -piston may again be med, to repeat .the above describedaction. VIt is thus seen that 4after .the pistol has been linitiallycocked manual- .ly .it -is vmerelynecessary to pull the trigger eachtime it is desired to -re a-cartridge and to then `'release the trigger.The pistol is Vautomatically recocked by the -recoil of the firedcartridge.

The parts carried in top frame lportion I 2 may be readily removed vforcleaning by unthreading .the .plug .member 24 from the forward Vend of`said :top frame portion. 'To facilitate this operation, the forward endof `said plug member `is formed with aligned radial notches '63, B3 intowhich the :edge of a. .coin orthe :blade of a screw V.driver may beinserted for .rotating said plug member with respect to the mentioned`top .frame portion I 2.

Secured .to the -sides of the grip portion 4I3 are cover .plates .64, 64.of suitable knurled =or other` 15 the like. from Figure .3 it will be:seen .that

access to the interior of grip portion I3 may be.

had by removing the cover plate 64'.

While a specific embodiment of an automatic pistol has been disclosed inthe foregoing description, it will be understood that variousmodications within the spirit of the invention may occur to thoseskilled in the art. Therefore it is intended that no limitations beplaced on the invention except as defined by the scope of the appendedclaims.

What is claimed is:

1. In a semi-automatic pistol comprising a pistol body having a hollowgrip portion, a slidable breech block with a firing pin extendingmovably therethrough, and a trigger pivoted at one portion thereof inthe pistol body, the combination of a hammer extending rearwardly incocked position andv pivoted at the forward end thereof in said pistolbody below the level of the breech block and having a notch in theforward end thereof, the hammer being rotatable upwardly into strikingcontact with the rear end of said pin, a sear bar pivotally mounted inthe grip portion and extending upward forwardly adjacent the hammer,resilient means biasing the upper end of the sear bar rearwardly intoengagement with the notch on the hammer to cock the latter andsimultaneously acting on said hammer to bias the hammer upwardly, a rodmember in the pistol body pivotally connected to the triggereccentrically of the pivot mounting thereof and having a rear dependinghook portion extending about but out of ,contact with the pivot mountingof the hammer and movable forwardly into engagement with said sear barin response to operative rotation of said trigger and thereby effectiveto release the sear bar from the notch on said hammer and allow thelatter to rotate upwardly and strike the firing pin under the bias ofsaid resilient means, the hammer being engageable by said breech blockas the latter is moved rearwardly to rotate said hammer downwardly tothe cocked position wherein the upper end of said sear bar engages inthe notch of said hammer, and further resilient means biasing the rodmember rearwardly with its rear depending hook out of operativeengagement with said sear bar.

2. In a semi-automatic pistol comprising a pistol body having a hollowgrip portion, a slidable breech block with a firing pin extendingmovably therethrough, and a trigger pivoted at one portion thereof inthe pistol body, the combination of a hammer extending rearwardly incocked position and pivoted at the forward end thereof in said pistolbody below the level of the breech block and having a notch in theforward end thereof, the hammer being rotatable upwardly into strikingcontact with the rear end of said pin, a sear bar pivotally mounted inthe grip portion and extending upward forwardly adjacent the hammer, anapertured rearwardly-extending projection upon the lower end of the searbar, an elongated spring guide member extending upwardly through theaperture in the latter projection and pivotally connected at the upperend thereof to the hammer eccentrically of the pivot mounting thereof, astop on the spring guide l member spaced a distance below the hammer, a

helical compression spring mounted on said spring guide member in aposition to engage downwardly upon said rearwardly-extending projectionof the sear bar and the stop on said spring guide in order to bias theupper end of said sear bar rearwardly into engagement with the notch onsaid hammer and to bias the latter upwardly, a

frod member in the pistol body pivotally con- -bar from the notch onsaid hammer and allow the latter to rotate upwardly and strike the nringpin under the bias of said helical spring, the hammer being engageableby said breech block as the latter is moved rearwardly to rotate saidhammer downwardly to the cocked Position wherein the upper end of saidsear bar engages in the notch of said hammer, a second spring engagingwith the rod member forwardly of the trigger and biasing said rod memberrearwardly with its rear depending hook out of operative engagement withsaid sear bar.

3. In a semi-automatic pistol comprising a pistol body having a hollowgri-p portion, and a slidable breech block with a ring pin extendingmovably therethrough, the combination of a trigger pivoted at oneportion thereof in the pistol body forwardly of the normal operativeposition of said breech block, a rearwardly-flaring hammer extendingrearwardly in cocked position and pivoted at the forward end thereof insaid pistol body below the level of the breech block and having a notchin the forward end thereof, the hammer being rotatable upwardly intostriking contact with the rear end of said firing pin, a sear barpivotally mounted at the lower end thereof in the grip portion andextending upwardly forwardly adjacent the hammer, a rearwardly-extendingapertured projection upon the lower end of the sear bar, an elongatedspring guide member extending upwardly through the aperture in thelatter projection and pivotally connected to the hammer eccentrically ofthe pivot mounting thereof. a stop on the spring guide member spaced adistance below the hammer, a helical compression spring mounted on saidspring guide member in a position to engage downwardly upon saidrearwardlyextending projection of the sear bar and against the stop onsaid spring guide in order to bias the upper end of said sear barrearwardly into engagement with the notch on said hammer and to bias thelatter upwardly, a rod member in the pistol body pivotally connected tothe trigger eccentrically of the pivot mounting thereof and having arear depending hook portion extending through the hammer and movableforwardly into engagement with said sear bar in response to operativerotation of said trigger and thereby effective to release the sear barfrom the notch on said hammer and allow the latter to rotate upwardlyand strike the firing pin under the bias of said helical spring, thehammer being engageable .by said breech -block as the latter is moved-rearwardly to rotate said hammer downwardly to the cocked positionwherein the upper end of said sear bar engages in the notch of saidhammer, a forward projection upon said rod member extending forwardly ofsaid trigger, a spring in said pistol body engaging against said forwardprojection and biasing the rod member rearwardly with its rear dependinghook out of operative engagement with said sear bar, said sear barhaving a transverse aperture therethrough above the normal p0- sition ofthe lower termination of the rear depending hook portion on the rodmember, and an eccentric cam portion -u-pon the hammer effective toraise said rear depending hOOk portion upon 'from effective contactwithssaid hook :portion and allow the' same under the bias of the.rst-mentioned helical spring -to engage resilientlyagainst the forwardend of the hammer and upon downward movement thereof .by means of thebreech :block to engage with the notch on said hammer,

and thereby cock the latter for a new cycle of operation.

ERNEST .J. SIMONSON.

J GAN CARTER :SIMONSON REFERENCES .CITED UNITED STATES PATENTS Number'Name Date 1,017,119 Ioborgv Feb. 13, 1912 1,138,379 Hammond May 4, 19151,405,765 Diehm Feb. 7, 1922 FOREIGN PATENTS Number Country Date 226,588Germany Oct. 6, 1910 464,054 France Jan. 5, 1914

